Author(s): Yun He; Cheng Liu
Linked Author(s): Cheng Liu
Keywords: Vortex; Pump sump; Suction intake; Critical submergence; PIV technique
Abstract: The flow in the vicinity of the suction intake in a pump sump is a complex three-dimensional turbulent flow. Good in-flow condition is necessary to ensure the pump operating in normal state and high efficiency; while bad one often causes uneven in-flow velocity distribution with vortex and swirl flow appeared. Previous research results of prediction of vortex hydraulic performance and vortex formation conditions have not convinced so far. In this paper, the formation and development process of varies of the vortices around the pump suction intake were observed with visualization techniques in the experimental study, and the flow behavior and vortex types around the pump suction intake were observed and recorded under different conditions of flow rate and water depth. The development process of different types of vortices under varies intake Fr number and relative submergence h/D were presented by dimensionless data. Flow fields around the intake with different horizontal and vertical sections were measured by using Particle Image Velocimetry (PIV) technique, and plenty of instantaneous and time averaged velocity fields and vortex fields were obtained. The empirical equation of the critical submergence for suction intake was put forward and the hydraulic characteristics of velocity distribution, vortex location, size and strength of near filed flow in the vicinity of pump intake were quantificationally presented.